This is a little more complicated than it might seem.

Depending on how the Switch version was designed, they may have to remove all proprietary Nintendo Switch-specific code before releasing anything. That could be a much bigger lift than simply cleaning up a few internal things.

For assets, there ...

I’m playing Factorio: Space Age on a Windows PC, with no mods enabled.
I’m using Valve’s new Steam Controller. I expected to be able to switch to the Steam Deck bindings so that the rear buttons — L4, R4, L5, and R5 — would be detected natively by the game.

Instead, these buttons are not detected ...